If you want to age like a 96-year-old Nobel Prize winner, get to work.

Arthur Ashkin became the oldest Nobel Laureate last year when he was awarded half the 2018 Nobel Prize in physics. The prestigious prize recognized his pivotal role in developing a technology that can levitate tiny objects with lasers.

Ashkin retired from Bell Labs (the spot where he did the Nobel-gaining research) in 1992, but he still ditches his cane and heads down to his basement to work every chance he gets.

“My lab is down there,” he told me during a recent visit to his Rumson, New Jersey home.

Ashkin is tinkering with his next invention, one he believes will win him another Nobel. At his workbench, he manufactures shiny tubes big and small from reflective paper and scotch tape. He thinks these will one day will make for a cheap solar-energy solution that will “save the world.”

“I do this many times a day” he said as he headed down his narrow basement stairs.

Ashkin’s inventive spirit may be part of the reason why his mind is still so sharp. Scientists who’ve studied so-called “superagers” – whizzes over the age of 65 whose memories are as sharp as any 25-year-old’s – say such people often share Ashkin’s curiosity and zeal for problem solving. Consistently posing tough questions and trying to solve hard problems can be a great way to ward off age-related mental decline.

“While nobody knows exactly why some people are superagers, we believe that one common factor is that they engage in demanding mental exercise,” superaging researcher and psychology professor Lisa Feldman Barrett recently wrote in The Guardian. “They continually challenge themselves to learn new things outside of their comfort zone.”

Barrett’s research suggests that engaging your brain in this way on a regular basis can help stave off beta-amyloid plaques, which can build up in the brain over time and are associated with conditions including dementia and depression.

“We suspect that people who seek and tolerate challenging tasks are helping to protect their memory, even if they have these plaques,” Barrett wrote.

Other researchers agree that picking up new skills as you age and committing to lifelong learning can help keep a mind sharp.

“Challenging your brain with mental exercise is believed to activate processes that help maintain individual brain cells and stimulate communication among them,” researchers at Harvard Health wrote in a blog post.

For Ashkin, this means continually questioning what he knows about how light particles operate.

“It’s sort of a mysterious particle,” he said. “When I took quantum mechanics, they said ‘it’s a wave which is everywhere. It’s a particle which is everywhere.'”